Mitral valve annuloplasty device with twisted anchor

ABSTRACT

The present invention relates to a tissue shaping device adapted to be disposed in a vessel near a patient&#39;s heart to reshape the patient&#39;s heart. The device comprises a first anchor and a second anchor adapted to be deployed by a catheter to engage a vessel wall while the first anchor is adapted to resist the compression of a first part of the first anchor and resist the expansion of a second part of the first anchor in response to a compressive force on the first part.

CROSS-REFERENCE

This application is a continuation of U.S. application Ser. No.17/466,706, filed Sep. 3, 2021, which is a continuation of U.S.application Ser. No. 16/568,055, filed Sep. 11, 2019, now U.S. Pat. No.11,109,971, which is a continuation of U.S. application Ser. No.15/368,467, filed Dec. 2, 2016, now U.S. Pat. No. 10,449,048, which is acontinuation of U.S. application Ser. No. 11/458,040, filed Jul. 17,2006, now U.S. Pat. No. 9,526,616, issued Dec. 27, 2016, each of whichare incorporated herein by reference in its entirety and to whichapplications we claim priority under 35 USC § 120.

BACKGROUND OF THE INVENTION

This invention relates generally to devices and methods for shapingtissue by deploying one or more devices in body lumens adjacent to thetissue. One particular application of the invention relates to atreatment for mitral valve regurgitation through deployment of a tissueshaping device in the patient's coronary sinus or great cardiac vein.

The mitral valve is a portion of the heart that is located between thechambers of the left atrium and the left ventricle. When the leftventricle contracts to pump blood throughout the body, the mitral valvecloses to prevent the blood being pumped back into the left atrium. Insome patients, whether due to genetic malformation, disease or injury,the mitral valve fails to close properly causing a condition known asregurgitation, whereby blood is pumped into the atrium upon eachcontraction of the heart muscle. Regurgitation is a serious, oftenrapidly deteriorating, condition that reduces circulatory efficiency andmust be corrected.

Two of the more common techniques for restoring the function of adamaged mitral valve are to surgically replace the valve with amechanical valve or to suture a flexible ring around the valve tosupport it. Each of these procedures is highly invasive because accessto the heart is obtained through an opening in the patient's chest.Patients with mitral valve regurgitation are often relatively frailthereby increasing the risks associated with such an operation. A deviceto perform mitral valve annuloplasty is therefore needed that can beimplanted percutaneously without opening the chest wall.

SUMMARY OF THE INVENTION

One aspect of the invention provides a tissue shaping device (such as apercutaneous mitral valve annuloplasty device) adapted to be deployed ina vessel to reshape tissue adjacent the vessel. The device comprises afirst anchor and a second anchor adapted to be deployed by a catheter toengage a vessel wall, wherein the first anchor includes a shapingfeature adapted to resist the compression of a first part of the firstanchor and resist the expansion of a second part of the first anchor inresponse to a compressive force on the first part, and a supportstructure disposed between and operatively connecting the first anchorand the second anchor. In some embodiments the anchors are adapted toengage a coronary sinus.

In some embodiments the first anchor comprises two entwisted wiresegments, possibly arranged in a figure-8 configuration having first andsecond arms coupled at at least one coupling point (formed from, e.g.,entwisted wire) as the shaping feature. In some embodiments, thecoupling point is substantially at an apex of the first anchor when theanchor is in its deployed configuration. In some embodiments, theanchor's width is greater than its height in its deployed configuration.

In some embodiments the device also includes an anchor lock adapted tolock the first anchor and/or the second anchor in an expandedconfiguration. In some embodiments the device has a coupler, which mayinclude a tether and a hitch wire, which is adapted to couple the deviceto a delivery tool. In some embodiments the coupler is further adaptedto release the device from the delivery tool. In some embodiments thedevice is adapted to be recaptured by the catheter.

One aspect of the invention is a method of performing mitral valveannuloplasty on a patient's heart. The method comprises percutaneouslydelivering a mitral valve annuloplasty device to a vessel in thepatient's heart, where the device comprises first and second anchors anda support structure disposed between and operatively connecting thefirst and second anchors, anchoring the first anchor of the mitral valveannuloplasty device in the vessel, resisting compression of a first partof the first anchor and resisting expansion of a second part of thefirst anchor in response to a compressive force on the first part, andanchoring the second anchor of the mitral valve annuloplasty device.

In some embodiments the first anchoring step comprises expanding thefirst anchor from a delivery configuration to a deployed configurationin which the first anchor engages the coronary sinus. In someembodiments, the anchor's width in the deployed configuration is greaterthan its height. In some embodiments the method includes locking thefirst anchor in the deployed configuration.

In some embodiments of the method the second anchoring step includesexpanding the second anchor from a delivery configuration to a deployedconfiguration in which the second anchor engages the coronary sinus. Insome embodiments the method includes locking the second anchor in thedeployed configuration.

In some embodiments the method includes capturing the first anchorand/or the second anchor within the catheter after the first anchoringstep. The capturing step may include advancing a catheter distally overthe anchor to place the anchor inside the catheter in the deliveryconfiguration.

In some embodiments the method includes applying a proximally directedforce on the mitral valve annuloplasty device after the first anchoringstep. In some embodiments the method includes uncoupling the device froma delivery tool after the second anchoring step. The uncoupling maycomprise releasing a hitch wire from the device and removing a tetherfrom the device.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 is a superior view of a heart with the atria removed.

FIG. 2 illustrates one embodiment of an intravascular device deployed ina coronary sinus.

FIG. 3 illustrates one embodiment of delivering an intravascular deviceto a desired location within a patient's body.

FIG. 4 shows one embodiment of an intravascular device with proximalanchor and distal anchor in their expanded and locked configurations.

FIG. 5 shows details of the distal anchor of FIG. 4 with a shapingfeature of two entwisted wire segments.

FIG. 6 illustrates an exemplary coupler that may be used with anintravascular device.

FIG. 7 shows an exemplary delivery tool that may be used to deliver anddeploy an intravascular device.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a medical device and uses thereof thatsupports or changes the shape of tissue near a vessel in which thedevice is placed. The present invention is particularly useful inreducing mitral valve regurgitation by changing the shape of orsupporting a mitral valve annulus. In preferred embodiments, the devicecomprises a distal anchor adapted to be anchored in the coronary sinuswhich resists a compression of a distal part of the anchor and anexpansion of a proximal part of the anchor in response to a compressiveforce on the distal part of the anchor. As used herein, “coronary sinus”refers to not only the coronary sinus itself, but also to the venoussystem associated with the coronary sinus, including the great cardiacvein.

FIG. 1 is a superior view of a heart 100 with the atria removed. Aspictured, the heart comprises several valves including mitral valve 102,pulmonary valve 104, aortic valve 106 and tricuspid valve 108. Mitralvalve 102 includes anterior cusp 110, posterior cusp 112 and annulus114. Annulus 114 encircles cusps 110 and 112 and functions to maintaintheir respective spacing to ensure complete mitral valve closure duringleft ventricular contractions of the heart 100. As illustrated, coronarysinus 116 partially encircles mitral valve 102 and is adjacent to mitralvalve annulus 114. Coronary sinus 116 is part of the venous system ofheart 100 and extends along the AV groove between the left atrium andthe left ventricle. This places coronary sinus 116 essentially withinthe same plane as mitral valve annulus 114, making coronary sinus 116available for placement of shaping device 200 in order to reshape mitralvalve geometry and to restore proper valve function.

FIG. 2 illustrates one possible embodiment of an intravascular tissueshaping device 400 which is deployable in coronary sinus 116. Asillustrated in FIG. 2, device 400 generally comprises an elongatedconnector 220 disposed between a distal anchor 240 and a proximal anchor260. Both distal anchor 240 and proximal anchor 260 are shown in theirdeployed, or expanded, configurations, securely positioned within thecoronary sinus 116. FIG. 2 further depicts, in phantom, a delivery tool300 comprising catheter 302 for delivering and positioning intravasculardevice 400 in the coronary sinus 116.

FIG. 3 illustrates one embodiment of delivering the intravascular deviceof the present invention to a desired location within a patient's body.An incision 80 is made in the patient's skin to gain access to a bloodvessel. The blood vessel may be, for example, the jugular vein. A guidecatheter 210 is advanced through the patient's vasculature until itsdistal end is positioned near the desired location for the intravasculardevice. After positioning the guide catheter 210, a delivery catheterand advancing mechanism 310 are inserted through the guide catheter 210to deploy the intravascular device at the desired location in thepatient's body. In preferred embodiments, the delivery catheter isadvanced until its distal end is inside the coronary sinus.

FIG. 4 shows one embodiment of an intravascular shaping device 400 withproximal anchor 402 and distal anchor 404 in their expanded and lockedconfigurations. In this embodiment, proximal anchor 402 is made from ashape memory metal wire, for example Nitinol, extending from a crimp406. Stress relief portions 408 of the wire extend distal to crimp 406.The wire extends upward from stress relief portions 408 to form vesselengagement portions 410 which cross to form a figure-8 pattern, asshown. Vessel engagement portions 410 and crimp 406 engage the innerwall of the coronary sinus or other vessel in which the device isimplanted. The vessel may be a superior vena cava as described in U.S.application Ser. No. 11/279,352, filed Apr. 11, 2006, now U.S. Pat. No.7,503,932. The wire also forms a lock loop 412 which interacts with anarrowhead-shaped element 414 extending from the proximal end of thecrimp to form the proximal anchor lock. The proximal side of proximalanchor 402 may be provided with variable slope recapture features, asdescribed in U.S. patent application Ser. No. 10/429,172, filed May 2,2003.

Likewise, the distal anchor is made from a shape memory wire extendingfrom a crimp 418. Stress relief portions 420 of the wire extend distalto crimp 418. The wire extends upward from stress relief portions 420 toform vessel engagement portions 422 which twist around one another,which is described in further detail below. Vessel engagement portions422 and crimp 418 engage the inner wall of the coronary sinus or othervessel in which the device is implanted. The wire also forms a lock loop424. A bent portion 407 of connector 426 interacts with wire portion 428and lock loop 424 to form a distal anchor lock to secure the distalanchor in an expanded configuration. Actuation of the proximal anddistal anchor locks is further described in U.S. application Ser. No.10/946,332, now U.S. Pat. No. 7,837,729, and U.S. application Ser. No.10/945,855, now U.S. Pat. No. 8,182,529.

Extending between anchors 402 and 404 are a substantially flat connector426 and a wire connector 428. In this embodiment, connectors 426 and 428are both made of shape memory metal, such as Nitinol. By spanning thedistance between proximal anchor 402 and distal anchor 404, connectors426 and 428 maintain the reshaping force on the tissue.

Fatigue resistant and stress relief characteristics of the connector 426and stress relief elements 420 and 408 are described in U.S. applicationSer. No. 11/275,630, filed Jan. 19, 2006, now U.S. Pat. No. 7,351,260.

Prior to use, tissue shaping devices such as those shown in FIG. 4 maybe stored in cartridges or other containers, such as described in U.S.application Ser. No. 10/946,332, now U.S. Pat. No. 7,837,729, and U.S.application Ser. No. 10/945,855, now U.S. Pat. No. 8,182,529, thendelivered to the coronary sinus or other vessel in a delivery catheter,as shown in FIG. 2.

As shown in FIG. 4, the wire forming the distal anchor 404 has one endpositioned within crimp 418. After exiting the distal end of the crimp,a first wire segment 452 of the distal anchor extends distally from thedistal crimp, then bends radially outward from the longitudinal axis ofthe crimp. The wire then bends back proximally and radially inward whereit twists around a second wire segment 462 at a coupling pointsubstantially at the anchor's apex. The wire then wraps around theconnectors 426 and 428 to form distal lock loop 424 before extendingradially outwards and distally where it becomes the second wire segment462. Finally, the second wire segment 462 bends proximally into thedistal end of the distal crimp 418.

As can be seen in FIGS. 1 and 2, the location of the coronary sinus inwhich the distal anchor may be deployed may be tapered as the diameteralong the length of the vessel decreases. Branching vessels may alsocontribute to a non-uniform diameter of the coronary sinus. Thus, thediameter of the coronary sinus where the distal part of the distalanchor contacts the coronary sinus wall may be narrower than thediameter where the proximal part of the distal anchor contacts thecoronary sinus wall. Thus, the vessel wall may exert a largercompressive force on the distal part of the anchor than on the proximalpart when the anchor is in a deployed configuration. This compressiveforce may cause compression of the distal end of the anchor, which canbe transferred through the anchor and cause an expansion in a proximalpart of the anchor. When such a compression occurs in the distal part,the distal anchor may not be able to anchor properly in the vessel. Thedistal anchor may compress and deform such that the amount of strain onthe vessel is not great enough to allow the distal anchor to remainanchored in place.

The exemplary embodiment shown in FIGS. 4 and 5 illustrates a devicewith an anchor shaping feature adapted to resist a compressive forceexerted on a distal part of an anchor and resisting an expansion of aproximal part of the anchor in response to a compressive force on thedistal part. The device of the present invention resists thiscompressive force on the distal part of the anchor and allows the deviceto anchor in place. Particularly, the distal anchor maintains a strainon the vessel which allows for the device to be anchored in the vesselto reduce mitral valve regurgitation, as described below.

As shown in FIG. 5, the distal anchor resists compression of its distalpart 502 and resists expansion of its proximal part 504 in response to acompressive force on the distal part 502 of the anchor. Statedalternatively, coupling of the anchor's arms via the twisted wire asshown acts to prevent a compressive force exerted on the distal part ofthe anchor from being transmitted through the anchor into the proximalpart of the anchor. The twist resists a distally exerted compressiveforce by creating a resistance to such a force.

While the anchor as described thus far resists a compressive force onthe distal part of the anchor, the anchor as adapted may also resist acompressive force on the proximal part of the anchor by creating aresistance when a compressive force is exerted on the proximal part ofthe anchor. Similarly, the proximal anchor of an intravascular devicemay also be adapted to resist compressive forces from a vessel in whichit might be deployed.

While the exemplary embodiments in FIGS. 4 and 5 show one full twist ofthe two segments of the distal anchor, it is understood that a differentnumber of twists may be used to carry out the intent of the inventionand the number of twists shown is not a limitation. In addition, it maybe desirable to have a distal anchor with more than two entwistedsegments, such as three, four, or more. Furthermore, anchor shapingfeatures other than entwisted wires may be used.

In some embodiments the anchor's width (e.g., the maximum distancebetween anchor arms 422 in FIG. 4) may be greater than its height (e.g.,the distance between crimp 418 and the twisted wire of anchor 404). Forexample, in some embodiments the distal anchor may be about 14 mm highand about 17 mm wide. The height and size may, however, vary while stillcarrying out the purposes of the invention.

In some embodiments the intravascular device comprises a coupler adaptedto couple the intravascular device to a delivery tool. FIG. 6illustrates an exemplary coupler in use with a different intravasculardevice that may be used with the intravascular device of this invention.The coupler comprises a loop 202 at the end of tether 201 and a hitchwire 204. Loop 202 extends through arrowhead-shaped element 414, and thehitch wire 204 passes through loop 202 and into the crimp, therebypreventing loop 202 from being withdrawn from arrowhead-shaped element414.

FIG. 7 shows an exemplary delivery tool 300 that may be used to deliverand deploy an intravascular device 400 via a catheter (not shown).Details of the operation of delivery tool 300 may be found in U.S.patent application Ser. No. 10/946,332, filed Sep. 20, 2004, now U.S.Pat. No. 7,837,729, and U.S. patent application Ser. No. 10/945,855,filed Sep. 20, 2004, now U.S. Pat. No. 8,182,529.

An exemplary method of performing mitral valve annuloplasty on apatient's heart is described. As indicated above, the intravasculardevice is preferably loaded into and delivered to a desired locationwithin a catheter with the proximal and distal anchors in a delivery orcollapsed condition. Medical personnel may deploy the distal end of theintravascular device from the catheter into the lumen of a coronarysinus by advancing the intravascular device or by retracting thecatheter, or a combination thereof. A delivery tool such as that of FIG.7 may provide for distal movement of the intravascular device withrespect to the catheter, and a tether may provide proximal movement ofthe device or for maintaining the position of the intravascular devicerelative to distal motion of a catheter. Because of the inherentrecoverability of the material from which it is formed, the distalanchor begins to expand as soon as it is deployed from the catheter.Using the delivery tool, the distal loop of the distal anchor is moveddistally so that the distal anchor further expands and locks in place tosecurely engage the coronary sinus wall and remains in the lockedexpanded configuration. The vessel may exert a compressive force on thedistal part of the distal anchor, due to, for example, the narrowingdiameter of the vessel. The distal anchor as adapted resists compressionof the distal part therefore resisting expansion of a proximal part inresponse to this compressive force. In addition, the greater width ofthe distal anchor in comparison to its height helps create strain on thevessel to increase the anchoring action.

Next, the intravascular device is tensioned by pulling on the tether toapply a proximally-directed cinching force on the distal anchor, therebymodifying the shape of the coronary sinus and adjacent nearby valveannulus tissue. Fluoroscopy, ultrasound or other imaging technology maybe used to detect when the device modifies the shape of the mitral valveannulus sufficiently to reduce mitral valve regurgitation withoutotherwise adversely affecting the patient. A preferred method ofassessing efficacy and safety during a mitral valve procedure isdisclosed in U.S. patent application Ser. No. 10/366,585, filed Feb. 12,2003. Once the device has been sufficiently cinched, the proximal anchoris deployed from the catheter to begin expansion. In some embodiments,the proximal anchor is deployed in the coronary sinus, but it may bedeployed in other vessels as well. The proximal loop of the proximalanchor is advanced distally over the arrowhead-shaped element by thedelivery tool to further expand and lock the proximal anchor, thusengaging the coronary sinus wall or other vessel and maintaining acinching force of the device on the mitral valve annulus. Finally, thecoupler that couples the intravascular device to a delivery tool can bereleased. A hitch wire is first withdrawn (by, for example, a hitch wireactuator of the delivery tool of FIG. 7), thereby releasing the loop soit can be pulled through the proximal lock, and thereby uncoupling theintravascular device from the delivery tool.

In some embodiments it may be necessary to move or remove theintravascular device after deployment by recapturing the device into acatheter. After the distal anchor is deployed and prior to initialdeployment of the proximal anchor, the distal anchor may be recapturedinto the delivery catheter by holding the intravascular device in placewith a the tether while advancing the catheter distally over the distalanchor so that the entire intravascular device is once again inside thecatheter. The distally directed force of the catheter collapses thedistal anchor to ease recapture into the catheter. In some embodimentsthe tether may be used to pull the intravascular device proximally whileholding the catheter stationary. Either motion, or a combination ofmotions, may be used to recapture the distal anchor. Similarly, afterdeploying the second anchor but prior to releasing the coupler asdescribed above herein, the intravascular device may be captured intothe delivery catheter by holding the device in place with the tetherwhile advancing a catheter distally first over a proximal anchor, overthe support structure, and finally over a distal anchor. The distallydirected force of the catheter collapses the anchors such that they canagain fit within the catheter. The tether may also be used to pull thedevice proximally while holding the catheter stationary. If the couplerhas been detached from the device prior to capture, the device may berecaptured into the delivery catheter or another catheter by graspingthe proximal end of the device with a tether or grasper and by advancingthe catheter distally over the device.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. A method of minimally-invasively treating mitralvalve regurgitation, the method comprising: advancing an intraluminalcardiac device in a collapsed configuration into a coronary sinus, theintraluminal cardiac device comprising a first expandable anchor, asecond expandable anchor, a connecting member extending therebetween, adistal end, a proximal end, and an axis that extends between the distaland proximal ends and along the connecting member; retracting a catheterproximally within the coronary sinus to cause the first expandableanchor to self-expand within the coronary sinus to an expandedconfiguration in which first and second arm segments of the firstexpandable anchor extend proximally from a distal end of the firstanchor and meet each other at an apex where the first segment passesover the second segment and then under the second segment and then overthe second segment, and in which the second segment passes under thefirst segment and then over the first segment and then under the firstsegment, and wherein in the expanded configuration the first segmentextends below the axis and away from the apex and forms a first stressrelief portion, the second segment extending below the axis and awayfrom the apex and forming a second stress relief portion, retracting thecatheter proximally within the coronary sinus to expose the connectingmember; pulling proximally on the cardiac device to reshape mitral valvetissue to reduce mitral valve regurgitation; retracting the catheterproximally within the coronary sinus to cause the second expandableanchor to self-expand within the coronary sinus to an expandedconfiguration; and releasing the intraluminal cardiac device from adelivery device.
 2. The method of claim 1, wherein in the collapsedconfiguration the apex is radially closer to the axis than in theexpanded configuration, and wherein in the collapsed configuration theapex is axially displaced relative to an axial position of the apex inthe expanded configuration.
 3. The method of claim 1, wherein the firstexpandable anchor is a distal expandable anchor.
 4. The method of claim3, further comprising pushing distally on the distal anchor to lock thedistal anchor in a locked configuration.
 5. The method of claim 1,wherein the first expandable anchor is a proximal expandable anchor. 6.The method of claim 5, further comprising pushing distally on theproximal anchor to lock the proximal anchor in a locked configuration.7. The method of claim 1, wherein the first expandable anchor is adistal expandable anchor and the second expandable anchor is a proximalexpandable anchor, and wherein pulling proximally on the cardiac deviceis initiated at a time prior to causing the proximal expandable anchorto self-expand within the coronary sinus.
 8. The method of claim 7,wherein pulling proximally on the cardiac device is initiated at a timesubsequent to retracting the catheter proximally within the coronarysinus expose the connecting member.
 9. The method of claim 1, whereinpulling proximally on the cardiac device comprises pulling proximally onthe delivery device.
 10. The method of claim 1, wherein the connectingmember comprises first and second connectors extending between thedistal and proximal anchors, and wherein retracting the catheterproximally within the coronary sinus to expose the connecting membercomprises retracting the catheter proximally within the coronary sinusto expose the first and second connectors.